Calcium Channel Blocker Drug Information(CCBs)

Annette (Gbemudu) Ogbru, PharmD, MBA

Dr. Gbemudu received her B.S. in Biochemistry from Nova Southeastern University, her PharmD degree from University of Maryland, and MBA degree from University of Baltimore. She completed a one year post-doctoral fellowship with Rutgers University and Bristol Myers Squibb.

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

What are calcium channel blockers (CCBs) and how do they work?

Calcium channel blockers are drugs that block the entry
of calcium into the muscle cells of the heart and arteries.

The entry of calcium
is critical for the conduction of the electrical signal that passes from muscle
cell to muscle cell of the heart, and signals the cells to contract.

It also is
necessary in order for the muscle cells to contract and thereby pump blood.

In
the arteries, the entry of calcium into muscle cells causes contraction of the
cells and thereby dilates (widens) the arteries.

Thus, by blocking the entry of
calcium, calcium channel blockers reduce electrical conduction within the heart,
decrease the force of contraction (work) of the muscle cells, and dilate
arteries.

Dilation of the arteries reduces blood pressure and thereby the effort
the heart must exert to pump blood.

Combined with decreases in the force of
contraction, this leads to a reduced requirement for oxygen by the heart.

Dilation of the arteries provides more oxygen-carrying blood to the heart.

The
combination of reduced demand for oxygen and increased delivery of oxygen
prevents angina or heart pain. (Angina occurs when the heart is not getting
enough oxygen relative to the amount of work it is doing.)